


The Three Heroes of the Underground

by SomeSmallLegoBricks



Category: Undertale (Video Game)
Genre: Aborted Undertale Genocide Run, Angst, At least compared to the end of the world, Characters React to Game Events, Gen, Sort of bittersweet?, Timeline Shenanigans, What happens to abandoned timelines?, no betas we die like men
Language: English
Status: In-Progress
Published: 2020-04-07
Updated: 2020-04-07
Packaged: 2021-03-02 05:00:33
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 1
Words: 3,795
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23529547
Author URL: https://archiveofourown.org/users/SomeSmallLegoBricks/pseuds/SomeSmallLegoBricks
Summary: Frisk never did a Genocide run. They barely reset at all. So they and their friends and family are all on the surface together and mostly happy in one form or another. But curiosity could always make them go all the way back, right? So in a misguided attempt at being helpful and a dash of schadenfreude from someone who knows what could have gone wrong, everyone is shown how awful things could have been. But it's not all awful, right?
Comments: 2
Kudos: 27





	The Three Heroes of the Underground

“Come on squirt, time for bed,” Undyne said. She ignored the very soft “nooo” of protest Frisk whispered as she picked them up, and gently held them in front of her. Undyne nodded to Alphys as they left the living room, letting her know to pause the movie for tomorrow. Normally Undyne would push for Frisk to finish the whole movie in one sitting and stay past their bedtime, but even she had to admit that Frisk had done enough.

It had been a long week for their mascot. Last Tuesday was the first year anniversary to the monsters emerging from Mt. Ebbot, and despite Papyrus taking up the mantle of ambassador, human politicians and monster media were both obsessed with making Frisk a part of every event and publicity stunt they could. Undyne knew there was a reason she didn’t like Mettaton, and seeing him drag Frisk around and putting them through event after event, ignoring their hesitancy and weak protests, cemented that feeling.

Frisk deserved to celebrate too, damnit! They’ve already earned the right to just watch the parades and have fun, not to be a toy pushed around for others’ amusement. Her anger bubbled to the surface, but Undyne kept a firm hold on it, not allowing any of it to strengthen her grip on the child she was carrying.

“I’m sorry I couldn’t watch the whole movie Unnie. Are you mad at me?” Frisk muttered.

“What? No!” Undyne was aghast. “I was just thinking of people who were pissing me off earlier today. You’ve done nothing wrong punk.”

Frisk hummed in response. 

As they were already in pajamas, Undyne immediately tucked them into bed. Maybe another kid Frisk’s age would complain about being tucked into bed and taken care of, but Frisk has never been insecure about how well they’re taken care of. Undyne knew with their family, Frisk was more confident in their reputation than even most adults. Either way, they were way too tired to make a fuss anyway.

Undyne smoothed out Frisk’s hair and said, “Sleep tight Frisk, you did a great job. We love you.”

The way Frisk snuggled into their bed and pillow almost made Undyne’s soul break from adorableness. Frisk’s breathing almost immediately started to even and slow, so Undyne left the bedroom, letting her friend fall asleep.

Back in the living room Alphys was talking on the phone with someone.

“-sn’t sound like you,” she said.

Undyne plopped down on the couch next to Alphys. As the person on the other end said something Alphys drew the name “Sans” into the air. Undyne nodded and pulled out her own phone.

There was only a text message from Papyrus letting Undyne know he and Sans weren’t going to make it to the movie night. It was something she already knew from Frisk, but appreciated the gesture anyway.

“Oh my god really?” Alphys asked. Undyne raised an eyebrow. “Well I guess I’ll leave you to that. I’m pretty sure Mettaton’s done, so you might even get to sleep in.”

A response.

“H-ha. Anyway. Bye.” Alphys hung up and turned to Undyne. “Papyrus is so tired after work that he’s actually going to sleep a full eight hours tonight!”

“Wow, uh,” Undyne was a little at lost with words. “Good for him, maybe? I honestly never can tell if he’s healthy or not. But man, he doesn’t do anything by halves, does he?”

“Yeah, n-no kidding. Mettaton must have really run him r-ragged, huh?” At the mention of the celebrity Undyne’s face visibly darkened. Alphys flinched. “S-something the matter Undyne?”

Undyne shook her head. “I don’t like that guy Al. I know he’s an old friend of yours, but he just rubs me wrong. He’s absolutely obsessed with being famous and performances and stuff. I’m not sure he can care about anything except for those things.”

Alphys laughed nervously. “Yeah, I k-kind of get where y-you’re coming from. He w-was more or l-less like that when I m-made his body. B-but he is getting better! Napstablook and Shyren are great at helping to ground him. Or a-at least, that’s what I think.”

A sigh escaped Undyne’s lips. “Yeah, I guess. But I’m going to make sure he doesn’t drag Frisk around or wear them out next time. Both him and Frisk need a better idea of boundaries.”

“Y-yeah, you have a point there,” Alphys said. “I should probably h-help when you decide to do that.”

“I’ll hold you up to that.”

There was a pause in the conversation where neither of them had anything else to say.

Undyne stretched out. “Anyway, I should go to bed now. I’m kind of wiped from all that celebrating today.”

Halfway from pushing herself from the couch, Alphys asked, “W-where are you going to bed? Frisk took your bed in the guest room.” Undyne froze. From the corner of her good eye, Undyne could see Alphys’s face get a bit red. “U-unless you w-want to to, um, stay in my bed?”

Undyne could feel herself heat up a bit when she heard that suggestion. “Ah, not tonight Alphys.” She plopped back down onto the couch. “Maybe in the future? I’ll just stay on the couch tonight.”

“O-oh, of course. Sorry Undyne, that was, uh, t-too much. I’m s-sorry that I suggested something so s-stupid and I-” Alphys rambled.

“Hey Alphys, Alphys. It’s fine,” Undyne cut her off. “It wasn’t stupid. Just not something I’m ready for. . . right now.” 

The yellow monster’s cheeks gave off a pleasant red hue as she processed the information. “Oh.” Before Undyne could say anything else Alphys shot from the bed. “I’ll-go-get-you-a-pillow-and-blanket-and-goodnight-Undyne!” she rushed out.

Next thing Undyne knew she was lying under a blanket on the couch and staring up at the ceiling. A small laugh echoed in the empty living room. She couldn’t believe that this was her life now. On the surface, everyone peacefully accepting monsters, Alphys is her girlfriend. She had more of a family than she could ever believe. She could imagine herself trying to go back in time to convince her past self this was going to be the future. She probably wouldn’t have believed her and tried to kill her on the spot.

Undyne weakly chuckled. She’s so, _so_ , lucky that she didn’t kill Frisk, and Frisk didn’t kill her. She was so lucky Frisk’s so forgiving and understanding to be friends with her after all of that. Undyne didn’t want to imagine a world where anything was different. She closed her eyes, and fell asleep.

Frisk’s eyes snapped open. They looked down to find themselves in their blue and purple sweater. The same one they wore underground. They definitely were not wearing this when they went to bed.

In fact, now that they were aware of it, they weren’t in their bed. They were standing up. Frisk was in a large, blank, light grey room. No exits, no entrance, no features. Frisk was distantly aware of the fact that the temperature was just barely cold. It felt like all over their body it was just one degree below being comfortable, no matter the clothing that covered it.

“Hello?” they asked tentatively.

“My child?” A familiar voice asked behind them.

Frisk spun around and saw their adoptive mother, wearing her old purple robe she wore back underground.

“M-mom?” Frisk asked. Oh no. If both of them were wearing their old underground outfits and are somewhere than Frisk last remembered, maybe a reset was forced somehow, maybe it messed up, maybe-

“Are you okay Frisk? Come here.” Before Toriel could finish, Frisk was already reaching for her. Frisk grabbed onto Toriel’s furred hand, and a smile of relief curled across their face. Toriel remembered them. She was actually here and Frisk could feel her warmth. It dispelled the cold around their hand and up part of their arm.

As Toriel checked them over, Frisk asked, “Where are we? Last thing I remember is Undyne putting me to bed.”

“I don’t know my child. The last thing I remember is going to sleep as well. I don’t see anyone else but that does not mean there is no one who caused this. Stay close,” she said, pulling Frisk behind her in a defensive stance.

Frisk started to move until they felt a cold pressure lock them in place. Looking up at Toriel, she didn’t seem to feel it, or notice Frisk’s predicament. Frisk fought with all their might to turn around, but it didn’t seem enough. There was a presence, something, behind them getting closer. It tickled the back of Frisk’s brain, but they weren’t entirely sure what-

“heya,” Sans greeted.

Frisk’s control over their body returned and they spun around. Toriel jumped in surprise and turned to see Sans standing on the other side of Frisk. He was dressed in the exact same outfit Frisk saw him in every day. But then again, he also wore in the Underground.

“probably not a good idea to keep frisk behind ya like that tori,” he said. “makes you vulnerable to sneak attacks.”

Toriel let out a shaky breath and extinguished her fireballs. “Oh, it’s just you my friend. Don’t sneak up on an old woman like me. You almost gave me a heart attack.”

“sorry t, hard to remember how hearts work when you don’t have one.” He winked. Sans glanced down from Toriel, back to Frisk. “you alright kiddo? any idea what’s goin’ on?” he asked.

It took Frisk almost a year to get used to the subtle changes in Sans’s face. His eyelids were showing some concern, but the tightness to his grin showed how confused he was too.

Frisk shook their head. “I woke up here after going to bed and so did Mom.”

Sans hummed. “maybe we’re in a weird shared dream? i can feel our souls here, so i know whatever’s going on, at least we’re together.”

Frisk smiled a bit. If that was proof that these people were really here than figments of the imagination, Frisk was going to take it.

“I have to disagree Sans,” Toriel interjected. “Whatever this is, I don’t think it’s a dream. For many years I have been able to lucid dream, and the sensations we’re experiencing are far too detailed and constant to be a dream.”

Before Frisk could respond a new person made themselves known.

“IS THIS WHY YOU ALL WERE ASKING ME TO TAKE LONG NAPS AT NIGHT? IF YOU’D TOLD ME YOU ALL GOT TO HANG OUT I WOULD HAVE STARTED BEFORE TODAY,” Papyrus said. 

Papyrus approached the trio from the other side of the room, where Frisk was certain he was not before. He was wearing his old “battle body” suit. The outfit he retired after officially taking up the role of ambassador. Frisk had to admit, they were used to his formal attire, a suit and tie, but the costume armor was a welcoming sight. Well, welcoming when not in this confusing situation.

“ALTHOUGH JUDGING BY YOUR EXPRESSIONS THIS IS NOT A NORMAL OCCURANCE TO SLEEPING AN EXTENDED PERIOD OF TIME, CORRECT?”

Toriel shook her head. “No Papyrus, this is just as new to us as you.” She paused. “Well, maybe more for you than us.”

“SO THEN WHAT IS THIS PLACE?”

Before Toriel could answer, a loud clang sound erupted behind Frisk. Everyone turned to the source.

Stood with slightly bent knees, as if it just landed, was a large, familiar figure in a suit of armor. She fully stood up and looked down at her gauntleted hands and then around the room. She took off her helmet.

“What the hell’s going on?” Undyne asked. 

Sans shrugged. “don’t know. our souls and magic are here, so this isn’t a normal dream or something. my g’s on prank show.”

Undyne scowled. “Mettaton.”

Papyrus eye sockets narrowed, in confusion and concern. “AS AMAZING AS METTATON IS, I DO NOT BELIEVE HE IS RESOURCEFUL ENOUGH TO KIDNAP US IN OUR SLEEP, AND TELEPORT US INTO AN ENCLOSED ROOM WITH NO EXITS AND A SOURCELESS LIGHT RIGHT WHEN WE WAKE UP.”

Frisk blinked. Oh yeah, there was no light source, was there.

But Papyrus’ concern did not lessen her scowl. “You weren’t one of his “volunteers” for his escape rooms.”

“BUT I THOUGHT MTT ESCAPE ROOMS WERE CANCELLED FOR SAFETY VIOLATIONS?”

Undyne nodded. “They were; me and Asgore had to make sure of it after a Vulkin almost died.”

“W-what’s that about you and Asgore?” A stuttering voice on the other side of Papyrus asked. Everyone turned around or shifted to see the source of the familiar voice.

“Babe!” Undyne shouted as she quickly maneuvered around everyone and scooped up Alphys into a hug.

Alphys squeaked out, “Undyne!” Her blush from physical affection has died down over the last year. But Frisk could still see a noticeable pinkness to her face. When Undyne put her back down Alphys’ attire was more visible. She was wearing the same lab coat she used to wear all the time Underground as the royal scientist.

Alphys readjusted her glasses and looked around. “Umm . . . can I ask, w-where are we?”

Undyne shrugged. “Best as we can tell, we’re stuck in this weird room with no exits. My gold’s on Mettaton doing this.”

Toriel looked off to the side. “Before we accuse people we know, we should keep our minds open to those we do not know about. I think it’s highly probable as I think we have a decent idea of each other’s capabilities,” she said.

“ALSO,” Papyrus said. “THE DREAM THEORY IS STILL PLAUSIBLE. ADMITTEDLY I AM NOT AN EXPERT IN SLEEP LIKE EVERYONE ELSE IS, BUT US FALLING ASLEEP AND WAKING UP HERE IS DEFINITELY CONNECTED.”

“hey, i think we’ve got another visitor,” Sans said, glancing out of the corner of his eye sockets.

Standing not ten feet from the group of monsters was the old, but very familiar sight of a large purple cape, so large it could be a curtain. At the top were two brass pieces of shoulder armor and two curved white horns peeking out from the head Frisk could not see from their vantage point.

Asgore slowly turned around, his hands in front of him and paws facing towards the ceiling. Frisk recognized his creased eyebrows and open maw. Even though they’ve only seen it on him once before. A look of horror when Asgore recognized Frisk as human.

“Where- I don’t, what’s,” Asgore stumbled out. Frisk had never heard Asgore get so confused or stuttery.

Undyne quickly intervened. She put up her hands and waved them back and forth. “We’re all fine Asgore. This is all just a weird shared dream!”

Asgore blinked and looked around. “So we’re not,” he paused, “at the barrier?” His eyes started to become more focused as he inspected the sourceless light and the defined walls surrounding them. 

“nope,” Sans said. “for some reason all of us are in whatever outfits we wore underground. and all of our souls are here so that means whatever’s going on we’re here together.”

Asgore let out an unsteady breath. “Okay good, that’s good. My apologies. I sometimes have nightmares where we are all back underground and everything is back to the way it was.”

Frisk looked down.

“heh,” Sans said. “that sounds terrible.”

Finally in control over his composure Asgore let his hands fall to his side. He turned to Toriel. “Is there anything else we know about this place?”

Toriel went over the mental checklist in her head. “I do not entirely believe this is a dream, although I’m not sure what else it could be. We all seem to have appeared here one after the other. Last thing anyone remembers is falling asleep.” Asgore nodded.

Undyne spoke up. “We were considering this was some sort of hoax or trick by Mettaton but I don’t think that’s a possibility anymore. I don’t think he’d have the guts to kidnap Asgore.”

“OH, I HAVE SOMETHING.” Papyrus said. Once everyone turned towards him he pointed towards one end of the room. “THERE IS A LARGE STRUCTURE FADING INTO EXISTENCE OVER THERE.”

Frisk whipped around and sure enough, there was a gray archway, much like the two purple ones on opposite ends of the underground. In between the two pillars however was a rectangle of blackness. It probably led to somewhere else but it was impossible to tell due to how inky black it was. For all Frisk knew, Sans painted that section of the wall black when no one was looking.

Everyone looked at each other. Everyone looked back at the inky black void.

Alphys said, “I d-don’t think it’s a g-good idea t-”

“NYAAAHH!” Undyne shouted as she charged through the archway.

“UNDYNE!” both Alphys and Papyrus shouted. Unlike Alphys, Papyrus continued, “WAIT FOR ME,” and ran after her.

Luckily, they didn’t vanish as if being consumed by unnatural shadow. Instead from everyone's perspective they ran into a very dark, black room. As they continued to run it was obvious that it was a very long dark black room. Undyne eventually stopped and looked around.

Everyone left in the gray room looked at each other.

“I suppose we should follow them,” Toriel said. “Strength in numbers and all.”

Asgore went ahead first, followed by Toriel pulling Frisk along, and Sans strolling behind. Frisk looked behind them to see Alphys tapping her claws nervously at the border between the rooms. Frisk pulled on Toriel’s hand to stop.

“Come on Alphys. We have to all go together,” they said.

Alphys looked down. “I know t-this may seem, um, c-cowardly but, what if, um, someone else s-shows up in this room? Shouldn’t s-someone stay here just in case? So they know w-what happened and where e-everyone went?”

Frisk looked up at the archway. “For some reason I don’t think that’s going to happen,” Frisk said. “And besides, if they need help they can just shout. I want us to stay together.”

Alphys stayed right in the threshold for a beat before she hesitantly stepped forward. Looking back up at Toriel, Frisk nodded. They got a warm smile in return and Toriel turned attention back to the endless dark and stepped forward.

Both Asgore and Toriel tried lighting up the space with fire magic but it seemed to do nothing. Either the darkness was supernatural or the room was black and there was nothing to reveal.

The four monsters and human in the middle walked. With no changing scenery it was difficult to tell if they were even moving. Or if time was passing.

“Hey Sans,” Frisk said. “Is this a prank? Did you bring us to your room somehow?”

Sans laughed. “heh, no way. you really think i’d do all this walking if my bed was nearby?”

Toriel looked strangely at Frisk. “What are you talking about my child?”

“Oh, back underground Sans gave-”

“Hey guys?” Undyne shouted from ahead. Frisk had to take a few large steps to look around Asgore and Toriel to see her. She and Papyrus were standing quite a distance away. “Is Sans still with you?”

Everyone looked at Sans but he seemed as confused as they were. “i’m still here undyne. why, what’s up?”

“Uh, I have no idea. I think we need your help.”

Everyone shared a look and then resumed traversing deeper into the void at a much faster pace. Frisk could see from behind Toriel when they made it when Asgore moved to the left to stand next to Undyne. He froze. Toriel instead moved to the right to stand next to Papyrus. She too froze. Frisk decided the space between Papyrus and Undyne was just wide enough for them so they squeezed their way through. Frisk’s brain stalled. They were distantly aware that Alphys moved somewhere to the left and Sans to the right.

Only a few feet away from the group were three very familiar monsters. One was Papyrus, even though Frisk was right next to him, standing straight and rigid. He looked so tired and yet his face had a weird sense of peace or maybe relief that Frisk had never seen before. Sitting on the black floor was another Undyne. Her armor was much more ornate, and perhaps magical? Frisk wasn’t sure. Many spikes were coming out of her form, around her shoulders, her gloves, her boots. And on the center of her chest was a large heart symbol. Her skin was just the littlest bit deformed. Her blue scales had long bumps of flesh sagging off like a raindrop frozen before falling. She was idly poking the dark floor with a blue energy spear. And the last of the duplicate trio was another Sans. Sans was sitting on the ground leaning back against an unseen barrier. His eyelights were off and his sockets were half-lidded. His skull was just barely deformed. Little bits of concave bumps were scattered across his skull. It was like his form was as tired as he was, staying in smooth lines and curves was just too much for the magic that held him together.

No one of Frisk’s group could say anything as they looked at the oh so slightly different duplicates.

The other Undyne looked over to the other Sans.

“Before we do this,” she said. “I just want to say while I hate it, I understand why you did what you did.”

The other Sans took a breath. “same.” 

She turned to the other Papyrus. “And I’m so glad it worked out for you, but don’t do something like that again.”

“same.” 

“I MUST REFUSE THAT ORDER UNDYNE, BECAUSE I WILL ALWAYS DO THE RIGHT THING, EVEN IF IT IS DANGEROUS,” Papyrus said.

The energy spear in Undyne’s hand dissipated and she pushed herself to stand. Sans did not. “Yeah, I know.” She turned her attention to everyone else. “Hi.” Her gaze slowly took in everyone standing across from her. She only briefly focused her attention on her counterpart and Frisk. “So, looking at everyone it looks like your human was the good one huh?”

Papyrus, Frisk’s Papyrus, asked, “OUR HUMAN UNDYNE?”

The other Papyrus said, “AS YOU MAY OR MAY NOT HAVE GUESSED WE ARE FROM DIFFERENT TIMELINES. ME, UNDYNE, AND SANS ARE NOT FROM THE SAME ONES BUT SIMILAR ONES. ONES WHERE THE HUMAN THAT CAME UNDERGROUND WEREN’T SO KIND AS YOURS. WE THOUGHT IT WOULD BE AN EDUCATIONAL EXPERIENCE FOR YOU TO UNDERSTAND WHAT COULD HAVE HAPPENED. ALSO, THE PERSON WHO TOLD US ABOUT YOUR TIMELINE SAYS IF WE DO SO, YOUR TIMELINE IS MORE LIKELY TO STAY NICE, FOR SOME REASON.”

“wait, who told you-”

“ANYWAY,” Papyrus interrupted. “WE PROBABLY SHOULD GET STARTED. I DON’T THINK WE’RE ALLOWED MUCH TIME FOR DILLY-DALLYING.”

**Author's Note:**

> I feel like Sans' involvement in Genocide is a bit too overhyped, so I wanted to explore abandoned genocide routes while properly acknowledging the two other "bosses" that make that route so good. And wanted to imagine how characters would react to such things. Also, sorry about the prologue, I just wanted to properly set up the work so I can focus on the good stuff. If anyone has suggestions to improve the set up I'm all ears.


End file.
